use activity context for FirstRunDialog

orientation of ApplicationContext always returns its orientation as
landscape in clamshell mode. While it is the root cause of this issue,
IIUC, we don't need to use application context for FirstRunDialog.

Bug: 37214882, 62414856
Test: manually tested as described in the issue

Change-Id: I478d1f53d1d6dec74f98d59c80085d163f09c551
(cherry picked from commit 457620629c641e95cb9621fc804f23e82c60c8b4)
2 files changed